Purpose :
Morphogenesis and architecture of the ocular lens is critically dependent on cell adhesive interactions and membrane cytoskeletal organization. A mechanistic understanding of the contribution of various scaffolding proteins regulating these cellular events remains to be established. Ankyrin-G (AnkG) is known to link the spectrin-actin cytoskeleton to membrane proteins and to participate in membrane subdomain organization. In this study, we explored the role of AnkG in lens development and integrity

Methods :
The expression and distribution profile of AnkG and identification of its co-existing proteins in the mouse lens were determined by immunoblot, immunofluorescence, immunoprecipitation and mass spectrometry analyses. AnkG lens conditional knockout (cKO) mice were generated using AnkG floxed and lens specific Cre transgenic mice (Le-Cre), and the eyes derived from these animals were evaluated by histological and histochemical analyses

Results :
Within the lens, AnkG is distributed intensely to the epithelium relative to fiber cells and immunoblot analysis of lens homogenates detected several protein products of AnkG splice variants. Immunoprecipitation analysis using AnkG antibody and lens homogenates identified co-precipitation of β-spectrin, connexin-50, N-cadherin, ezrin, αN-catenin, β-catenin, aquaporin-0 and ZO-1. AnkG cKO mice (one month-old) showed a marked decrease in eye and lens weight and extensive degeneration of the lens compared to littermate AnkG floxed mice. Neonatal (P1) and P30 AnkG cKO mice exhibited abnormal lens shape with shortened and thinned epithelium containing a reduced number of nuclei. The lens epithelium from P1 AnkG cKO mice exhibits disorganized distribution of E-cadherin, β-catenin, connexin-50 and β-spectrin, together with robust expression of α-smooth muscle actin relative to littermate controls. Interestingly, some of the mice that were heterozygous for the AnkG floxed allele and Cre positive also exhibit a cataractous phenotype

Conclusions :
Taken together, this ongoing study reveals an essential role for AnkG in maintaining lens epithelial phenotype, morphogenesis, integrity and shape by regulating epithelial cell adhesive interactions, channel protein and spectrin-actin cytoskeletal membrane organization. To the best of our knowledge this is the first study illuminating the importance of AnkG in lens development and function

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.